This longitudinal study will identify specific pathways that are responsible for the link between personality and health in later life. It will employ enhanced assessment methods, including informant reports, interviews, and self-report measures of adaptive as well as maladaptive variants of personality traits. We will investigate psychosocial factors, biological pathways, and personality changes in relation to subjective health, diagnosis and treatment for specific medical disorders, and mortality. Personality traits will be considered both in terms of their protective (e.g., conscientiousness and health behaviors) and harmful functions (e.g., neuroticism and stressful life events). At the psychosocial level of analysis, three mechanisms will be examined as important mediators and moderators: health behaviors (e.g., use of tobacco and alcohol); exposure to environmental adversity (e.g., trauma, neglect, and on-going stressful life events); and social integration (e.g. intimate relationships, social networks, and community involvement). At the biological level of analysis, three additional mechanisms will be considered: neuroendocrine functioning (cortisol); immune system functioning (inflammation); and chromosomal stability (telomere length). Pathways between personality and health will be considered in terms of stable trait levels as well as personality change. Our data will allow us to examine health disparities, testing a variety of hypotheses concerned with both risk and resilience. For example, we will study the role that personality characteristics (e.g., mistrust and impulsivity) play in moderating the relation between environmental adversity and chronic illness. The study will extend data collection with a sample of participants that has already been studied for six years, beginning in 2007. The participants form a representative, ethnically diverse (33 percent African-American), community-based sample of 1,630 persons between the ages of 55 and 64 (when entering the study) ---those approaching the challenges of later life. All participants completed comprehensive assessments of personality, health, and social adjustment at baseline. Stressful life events, social adjustment, and changes in health were then monitored at regular six-month follow-up assessments, leading up to a second assessment of personality, which was conducted 2.5 years after baseline. During Phase II (the next project period), we will conduct two more personality assessments: the third will occur three years after the second, and the fourth will occur two years after the third. We will also collect blood samples to be used for measuring biomarkers at the time personality assessments three and four. Regular follow-up assessments of health, health behaviors, stressful life events, and social functioning will continue to be completed at four regular 6-month intervals following the third assessment. This project fills an important gap in knowledge regarding mechanisms that explain the connection between personality and health.